1. Field of the Invention
The present invention relates to a setting tool including an axially displaceable drive piston having a sealing element and a stem, a piston guide for guiding the drive piston, a bolt guide adjoining the piston guide at a setting direction side of the piston guide, and a buffer member located in a guide bore of the piston guide between the sealing element of the drive piston and the bolt guide and surrounding the drive piston stem.
2. Description of the Prior Art
In setting tools, the buffer member is designed for absorbing an excess kinetic energy of the drive piston. By absorbing the excess kinetic energy, the buffer member prevents the drive piston and components which surround the drive piston of the setting tool from being damaged. A buffer member of the type described above is disclosed, e.g., in U.S. Pat. No. 3,249,279. The buffer member, which is disclosed in the patent, is located in the piston guide between the sealing element of the drive piston and the bolt guide. The buffer member is formed as a sleeve-shaped part surrounding the stem of the drive piston. The buffer member is directly impacted by the drive piston and is compressed to a greater or lesser degree dependent on the motion energy of the drive piston. During change of the tooling of the setting tool or during servicing of the setting tool, the buffer member can easily be lost. Because the setting operation can be conducted even without the buffer member, its absence will only then be noticed when the tool itself or its tooling becomes damaged because of an improper operation resulting from an excess motion energy of the drive piston, which should have been absorbed by the buffer member.
An object of the present invention is to provide a setting tool including a buffer member arranged in the piston guide bore between the drive piston and the bolt guide and which can be displaced, to a limited extent, parallel to the setting direction substantially wear-free.
Another object of the present invention is to provide a setting tool including a buffer member which is arranged as discussed above and has a good side support along the outer contour of the buffer member.
A further object of the present invention is to provide a setting tool including a buffer member arranged between the drive piston and the bolt guide without a possibility of being lost.